Wu Li, Zhao Wei, Yang Ruijin, Yan Wenxu, Sun Qianyan
State Key Laboratory of Food Science and Technology and School of Food Science and Technology, Jiangnan University, No. 1800, Lihu Road, Wuxi, 214122, China.
School of Food Science and Technology, Jiangnan University, No. 1800, Lihu Road, Wuxi, 214122, China.
J Sci Food Agric. 2016 Aug;96(10):3334-41. doi: 10.1002/jsfa.7512. Epub 2016 Jan 7.
Pulsed electric field (PEF) processing is progressing towards application for liquid egg to ensure microbial safety. However, it usually causes protein aggregation, and the mechanism is still unclear. In this study, egg white protein was applied to investigate the changes in protein structure and mechanism of aggregates formation and a comparison was made with thermal treatment.
Soluble protein content decreased with the increase of turbidity after both treatments. Fluorescence intensity and free sulfhydryl content were increased after being treated at 70 °C for 4 min. Less-remarkable changes of hydrophobicity were observed after PEF treatments (30 kV cm(-1) , 800 µs). Soluble and insoluble aggregates were observed by thermal treatment, and disulfide bonds were the main binding forces. The main components of insoluble aggregates formed by thermal treatment were ovotransferrin (30.58%), lysozyme (18.47%) and ovalbumin (14.20%). While only insoluble aggregates were detected during PEF processes, which consists of ovotransferrin (11.86%), lysozyme (21.11%) and ovalbumin (31.07%). Electrostatic interaction played a very important role in the aggregates formation.
PEF had a minor impact on the structure of egg white protein. PEF had insignificant influence on heat-sensitive protein, indicating that PEF has potential in processing food with high biological activity and heat sensitive properties. © 2015 Society of Chemical Industry.
脉冲电场（PEF）处理技术正朝着应用于液态蛋以确保微生物安全的方向发展。然而，它通常会导致蛋白质聚集，其机制仍不清楚。在本研究中，应用蛋清蛋白来研究蛋白质结构的变化以及聚集体形成的机制，并与热处理进行比较。
两种处理后，随着浊度增加，可溶性蛋白质含量降低。在70°C处理4分钟后，荧光强度和游离巯基含量增加。PEF处理（30 kV cm(-1)，800 µs）后观察到疏水性变化不太明显。热处理观察到可溶性和不溶性聚集体，二硫键是主要结合力。热处理形成的不溶性聚集体的主要成分是卵转铁蛋白（30.58%）、溶菌酶（18.47%）和卵清蛋白（14.20%）。而在PEF处理过程中仅检测到不溶性聚集体，其由卵转铁蛋白（11.86%）、溶菌酶（21.11%）和卵清蛋白（31.07%）组成。静电相互作用在聚集体形成中起非常重要的作用。
PEF对蛋清蛋白结构影响较小。PEF对热敏感蛋白影响不显著，表明PEF在加工具有高生物活性和热敏感特性的食品方面具有潜力。© 2015化学工业协会。
